Variable-speed gear.



No. 830,159. BATENTED SEPT. 4, 1906.

W. E. MARX.

VARIABLE SPEED GEAR. APPLIOATION FILED BEPT.17.1904.-

2 SHEETS-SHEET 1.

m: "only: PETERS cav, WASHINGYON, 0. cs

PATENTED SEPT. 4, 1906.

W. E. MARX. VARIABLE SPEED GEAR. APPLICATION I'I'LED SEPT, 17,1904.

2 SHEETS-SHEET 2.

ms NORRIS PEYERS co, wnsnmarou, n. c.

WILHELM EDUARD MAR-X, OF LEIPSIG, GERMANY.

VARIABLE-SPEED GEAR.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed September 17, 1904. Serial No. 224.887.

To all whom, it may concern:

Be it known that I, \VILHELM EDUARD hIARX, engineer, a subject of theKing of Saxony, residing at Leipsie, in the Kingdom of Saxony and GermanEmpire, have invented certain new and useful Improvements inVariable-Speed Gears for Engines and Vehicles, of which the following isa full, clear, and exact description.

This invention relates to an improvement in variable-speed gears forengines and vehicles by means of which the rotary speed can be variedwithout interrupting the continuity of the driving action.

In carrying my invention into effect I proceed in or in ab out thefollowing manner, making reference to the accompanying drawings, whereinFigure 1 shows a side view, partly in section on line 1 1, Fig. 2, ofone form of this speedgear; Fig. 2, a view from below of this form. Fig.3 is the longitudinal section of a sleeve and a cross-piece attached toit. Fig. 4 is the cross-section of the sleeve, the crosspiece, and tworoller-holders. Fig. 5 is a ,plan view of. the crosspicce; Fig. 6, aside view of a modified construction; Figs. 7 and 8, views of the lowerportion of this modification from below. Fig. 7 is shown partly insection. Fig. 9 is partly a central cross-section, partly an endelevation, of this modified form. Fig. 10 is a central horizontalsection of the sleeve of the modified construction. Fig. 11 is thecross-piece of it. Fig. 12 is a doubleforked guide; Fig. 13, aslide-frame in longitudinal section, and Fig. 14 this frame in centralcrosssection.

To carry this invention into effect, I arrange a shaft 1, firmly seatedin bearingblocks, and loosely on this shaft I provide two independentstep-pulleys 2 3 in such a manner that the pulleys with the largestdiameter are close to each other, as is shown in the form of thisvariable-speed gear illustrated by Figs. 1. and 2. In order tofacilitate the action of this gear, the single steps of the pulleys passinto each other by the conieal planes Beyond the step-pulleys 2 3 andsliding upon a guide-shaft 10 there is mounted a sleeve 11, which can bemoved in direction of the arrows A B by the shaft 9, firmly seated inthe sleeve. The sleeve of the form represented in Figs. 1 and 2 ismounted above a cross-piece 14, which is slidably set on a vertical bolt26, secured to the sleeve preferably.

The vertical movement of the cross-piece is effected by screws 22 whenthe tension of the bolt 4 is to be increased. The female threads ofthese screws are cut into the ends of the longitudinal portion ofcross-piece 14. The free ends of the screws engage with pans 27,provided at the bottom of the sleeve 11. The other arms of thecross-piece 14 are provided with two roller-holders 13 13, which arepivotally suspended from the above-mom tioned cross-arms by bolts 15.These rollerholders are capable of being turned on their bolts 15, andthey carry guide-rollers 5 to 8, pivotally arranged on pins 12. Fortransmitting, the rotary motion on the endless belt 4 is provided, whichruns over the step-pulleys 2 3 and the rollers 5 to 8. On the shaft 1 isloosely mounted a pulley 25 and close to it a pulley 28, which is firmlyconnected to the step-pulley 2. After having stretched the endless belt4 by means of the screws 22 the gear (represented in Figs. 1 and 2) actsthus: hen the sleeve 11 is moved by the shaft 9 in direction of thearrow A, the endless belt 4 slips down to the following smaller step ofthe step-pulley 2. At the same time the belt when being in motion willcreep up to the following larger step ofthe step-pulley 3. As beforementioned, this creeping movement of the belt onto the larger step ofpulley 3 is facilitated by the cones 33.

Now it is clear that the steppulley'2,being coupled with thedriving-pulley 28 and having a uniform motion, will cause the rotarymovement of the step-pulley 3 to diminish as soon as the sleeve 11 hasbeen moved in the direction of the arrow A. If the displacement of thebelt, on the contrary, takes place in the direction of the arrow B, thespeed of the step-pulley 3 will be increased, for now the endless belt 4slips over the smaller step of the step-pulley 3 and creeps up to thelarger step of the step-pulley 2.

The modification represented in Figs. 6 to 14 is characterized by thefact that the steppulleys 2 3 are loosely arranged on the shaft 1 insuch a manner that the pulley-steps with the smallest diameter are closeto one another. Parts of the guide-shaft 10, which carries the sleeve11, are provided on both sides with teeth 30, which engage with toothedwheels 31, pivotally mounted in the sleeve 11 on pins 19. These wheels31 are in engagement with driving-wheels 18, the latter being firmlyconnected with two pins 15, which unite two guide-frames 13 with thecross-piece 14. A bolt 26 is screwed into sleeve 1 1, which forms avertical guide for the cross-piece 14:, allowing it a limited movementin vertical direction. The guide-forks 13 carry slide-frames 20, whichhave guiderollers 5 to 9 seated rotatably on pipe 12. When the belt 4has been put in place, the sliding frames 20 are by thetension of thebelt, with their shoulders 29 against cams 16 17, which are firmlyconnected to the two pins 15.

In order that the action of the modification represented in Figs. 6 to14 may be better understood, I refer to the position shown in Fig. 6. Inthis figure the two cams have a position such as represented in Fig. 7,where it may be seen that the adj oined pieces 29 of all four slidingframes 20 stand against the shorter ends 16 of the cams in consequenceof the tension of the belt 4. The indentations and the diameter of thegraduated circle of the bolts 15 and extensions 18 18 are so calculatedthat when the sleeve is moved in the longitudinal direction of thestep-pulleys to the extentof one-half the width ofa step the cams 16 16are rotated ninety degrees. The distance between the guide-rollers 5 7and 6 8 depends on the size and form of the cams 17, by which saidrollers are moved to the intended distanoeviz., a full step of thesteppulley. According to this action the two guide-rollers 7 8 do notadvance, so that the belt remains in its position on that step on whichit has been before the movement of the sleeve 11 began. It is easilyunderstood that the belt lying above the two guide-rollers 5 and 6 willcreep up to the following higher step if said guide-rollers are moved awhole step forward. If the sleeve 11 be further moved in the samedirection to the extent of half a step, the two cams 16 16 are rotatedonce more to the extent of ninety degrees, and consequently the pulleys5 6 retain their position, but the guide-rollers 7 8 travel a whole stepforward. The belt lying above these two pulleys will therefore slip downto the following smaller step.

In the speed-gear shown the pulley 32 is firmly connected with thestep-pulley 3 in order to transfer the movement. The construction may,however, be changed in such manner that theshaft 1, that is firmlyconnected with the step-pulley 3, is seated r'otary.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. A variabl-speed-transmission gear comprising a pairof stepped cone-pulleys coaxially arranged and having their basesopposite one another, a carriage movable parallel to said pulleys, andhaving a pair of swinging arms thereon, idler-pulleys on said arms, anda belt extending over said idler-pulleys and said cone-pulleys andarranged to direct said idler-pulleys into alinement with the particu-'lar cone-pulley opposite which they are located, by the tension of thebelt.

2. In a variable-Speed-transmission gear, apair of stepped cone-pulleysin axial alinement and having, their bases opposite one another, acarriage arranged to move parallel to said pulleys, idlers on saidcarriage, a belt extending over said idlers and said pulleys, meanswhereby said idlers are guided to have a forward and back movementindependent of the carriage, and cam means for imparting such movementwhen the carriage is shifted, whereby the forward idler-pulleys shiftthe belt to a smaller step of one of the cone-pub leys before the rearidler-pulleys shift the belt to a larger step of the other cone-pulley.

In witness whereof I subscribe my signature in presence of twowitnesses.

WILHELM EDUARD MARX.

Witnesses ARNo KREBS, RUDOLPH FRICKE.

